POS1314 VALIDATION OF A PEDIATRIC-SPECIFIC ULTRASOUND SCORING SYSTEM FOR THE EVALUATION OF WRIST, FINGER, AND ANKLE SYNOVITIS
Authors: P. Vega Fernandez, T. Hennard, K. Rogers, A. B. Meyers, A. Cassedy, T. Ting
Journal: Annals of the Rheumatic Diseases (2022)

Background Juvenile Idiopathic Arthritis (JIA) is the most common chronic rheumatic disease in children. Clinical evaluation of arthritis is a subjective measurement. Musculoskeletal ultrasound (MSUS) is increasingly being utilized in children. In order to provide objective assessments of arthritis, reliable and validated MSUS scoring systems are needed. Recently, a joint-specific scoring system for the assessment of arthritis of the pediatric ankle, wrist and finger joints were proposed[1, 2]. Objectives This study aims to further validate the MSUS scoring system for the assessment of finger, wrist, and ankle arthritis Methods JIA patients with finger, wrist, and ankle arthritis as per expert clinician evaluation are eligible for this study. A comprehensive wrist, ankle, and finger (2-5 th metacarpal and 2-5 th proximal interphalangeal joints) MSUS examination by an American College of Rheumatology MSUS certified pediatric rheumatologist is performed an all enroll subjects. MSUS are scored using the semiquantitative (grade 0 to 3) scoring systems previously proposed. A subset of participants receives an MRI with contrast of the targeted joint immediately after MSUS performance. MRI findings are read for presence of synovitis, tendonitis and enthesitis by a pediatric radiologist with expertise on musculoskeletal imaging. For the analysis of the current report, MRIs were classified as having presence or absence of findings of JIA disease based on the pediatric radiologist expert opinion. MSUS were classified as normal (grade 0 and 1) or abnormal (grade 2 and 3). Cohen’s Kappa Coefficient was used to assess the level of agreement between MSUS (normal and abnormal) and MRI with contrast (absence or presence of disease) for each targeted joint. Tetrachoric Correlation was used to assess the strength of the association. Fisher’s Exact test was used to determine statistical significance at p &lt; 0.05 level. Results A total of 52 children aged 2 – 18 years old have been enrolled in this study. To date 20 MSUS of the finger(s), 33 MSUS of the wrist, and 43 MSUS of the ankle joints have been collected. Three MRI of the 2-5 fingers (12 fingers total), 6 MRI of the wrist, and 5 MRI of ankle have been obtained through the study. Preliminary results of this effort reveal that for the ankle joint there is moderate agreement (Kappa coefficient 0.53 (confidence interval (CI)=0.14-0.92)) between MRI and US and a strong positive tetrachoric correlation (0.79) (p = 0.03). While the Kappa coefficient for comparing MRI and US finding on wrist joint indicated moderate agreement (Kappa 0.62 [0.15-1.00]) with a strong tetrachoric correlation (0.83) the Fisher’s exact test indicated a trend rather than statistically significant results (p = 0.07). The Kappa coefficient for MCPs and PIPs joints indicated strong agreement between MRI and US (Kappa 0.83 [CI=0.52-1.00] and 0.80 [CI=0.43-1.00] respectively) and were supported by an almost perfect Tetrachoric Correlation of 0.99 (p &lt; 0.01). We anticipate to complete enrollment of subjects by the summer of 2022. Analysis of collected data is underway. Conclusion The strong to moderate association of MSUS with contrast-enhanced MRI, suggest that MSUS can provide an objective and accurate assessment of ankle, wrist and finger arthritis at the bedside. Further refinement and validation of these pediatric-specific MSUS scoring systems may support the use of MSUS as a clinical tool and outcome measure in JIA. References [1]Vega-Fernandez P, D.R.D., Oberle E, Bukulmez H, Lin C, Shenoi S, Thatayatikom A, Woolnough L, Corbin K, Benham H, Brunner E, Henrickson M, Ballenger L, Haro S, Schutt C, Proulx-Gauthier J, Janow G, Altaye M, Cassedy A, Roth J, Ting T., Novel Ultrasound Image Acquisition Protocol and Scoring System for the Pediatric Ankle [abstract]. Arthritis Rheumatol, 2020. 72 . [2]Vega-Fernandez, P., et al., The MUSICAL pediatric ultrasound examination - a comprehensive, reliable, time efficient assessment of synovitis. Arthritis Care Res (Hoboken), 2021. Acknowledgements Project supported by the Center for Clinical &amp; Translational Science &amp; Training (CCTST) at the University of Cincinnati funded by the National Institutes of Health (NIH) Clinical and Translational Science Award (CTSA) program, grant 2UL1TR001425-05A1 and KL2 (2KL2TR001426-05A); and a Diversity and Health Disparities Award from the Cincinnati Children’s Hospital Medical Center. Disclosure of Interests None declared